Fishless reef tank

[Hopper123]

Hi do any of u run fishless reefs with just inverts and corals, just wondering if a mixed reef tank would run successfully like this

 

[Lavey29]

A lot of coral vendors frag tanks are fishless and some just use a few utilitarian fish and inverts

 

[JTP424]

I don't see why it wouldn't! You would have to be careful with obvious risks like pests and algae.
Algae can be handled with inverts etc, some pests are only easily eradicated/kept at bay with fish (I'm thinking bristleworms etc) Like mentioned previously, it would essentially be a frag tank. So regular water changes would be a must I believe.

 

[Dkmoo]

Long term, you will run into nutrient issues from lack of an N and P source - assuming you are not feeding the inverts.

EDIT: IMHO fish waste is a very underrated reef fertilizer

 

[betareef]

Long term, you will run into nutrient issues from lack of an N and P source - assuming you are not feeding the inverts.

EDIT: IMHO fish waste is a very underrated reef fertilizer

I would have big, and/or many larger inverts that require feeding. Maybe a lobster or two? Large molluscs? Sea hares? Clams? Mussels?

 

[Dkmoo]

I would have big, and/or many larger inverts that require feeding. Maybe a lobster or two? Large molluscs? Sea hares? Clams? Mussels?

As long as you are introducing new sources of N and P it will be fine. As corals grow, C N and P will be locked in the biomass. Carbon is readily available and can even be pulled from ur ambient air so just need to periodically add additional N and P as you monitor the NO3 and PO4 levels.

 

[Doctorgori]

I posted a similar thread a few months back, and Im also about to do a build experiment to see if it works long term…my guess is it wont work … but we will see

 

[sixty_reefer]

Hi do any of u run fishless reefs with just inverts and corals, just wondering if a mixed reef tank would run successfully like this

If you were to add a ammonia source and phosphate as needed you should be fine, putting the needs of coral aside that can easily be dosed you would still have to establish a decent nitrification and dinitrification process to have a microbial balance in the tank and a balance nitrogen cycle.
Meaning that you would have to set up the tank as you would for a fish environment with plenty of live or dead rock to ensure a good environment for both parts of the cycle.
Depending if you feeding the tank or not you may have to also add organic carbon to complete the dinitrification cycle.

 

[twentyleagues]

Now that I have been back going on two years I remembered I have a love hate relationship with fish and corals together. I am sure it can be done but nutrient management is going to need to be addressed, basically feeding your corals. Also pest control, algae, bugs stuff like that fish can help greatly in those cases and I do look at fish in my system as possible janitors of a sort. Inverts can do some of that stuff but I dont know to many inverts that will handle bugs like a wrasse can. Of course you can always set up a coral qt and be diligent.

 

[Hopper123]

It's just a thought I have 5 fish in my tank it's been running a year I was thinking of replacing the fish with more shrimp I already have a boxer , fire , pistol and peppermint shrimp but would like to add more but have a six line wrasse who I think will eat new additions

 

[stewy14]

how big u plan to make the tank?

 

[twentyleagues]

It's just a thought I have 5 fish in my tank it's been running a year I was thinking of replacing the fish with more shrimp I already have a boxer , fire , pistol and peppermint shrimp but would like to add more but have a six line wrasse who I think will eat new additions

It can be done. Just fish food and poop can go along way to feeding your corals.

 

[Subsea]

As long as you are introducing new sources of N and P it will be fine. As corals grow, C N and P will be locked in the biomass. Carbon is readily available and can even be pulled from ur ambient air so just need to periodically add additional N and P as you monitor the NO3 and PO4 levels.

Kudos to this post.

I run many fishless systems. For trace elements, I add concentrated liquid kelp every other day. On macro growout tanks, I add ammonia every day.

 

[MichaelM]

I have mixed experiences with fishless tanks. This is my old 10l tank:

As you can see there are not really any growth tips on the Montipora. There is only one actively growing branch in the back and some encrusting in the left. The LPS in the front were steadily growing. The brown Acro frag in the top right was not really branching (just for a very brief time) and just encrusting and thickening. The Monti plate was always growing.

The next image is my new 35l tank in which I am now trying to focus more on Acropora.

The picture is already a bit older. The Millepora frag was the last survivor of a batch of 5 Acro frags. I had problems with bottoming out PO4 which resulted in RTN in the rest. The Milli is now also dead. It just slowly STN´d. After a couple of months and some good growth on the Montipora I recently tried a new batch of 5 Acro frags which already started to STN again

So my experience: LPS and Montipora are not really problematic (the Milka in the left is not really growing btw). But even with the Montipora there where only more or less short growth spurts and then it went stale for a while. Acros on the other hand really seem to have a problem and I guess it has to do with nutrition. I am adding ammonium, PO4, vinegar (twice daily) and some food (Reef Roids and FM Min S 2-3 times/week).

 

[FishTruck]

I've been struggling with a fishless frag tank. It is the only place where algae keeps getting out of control despite snails and crabs. The main tank (same system) is loaded with fish and no algae problems.